A marine outboard engine generally comprises a bracket assembly that connects the drive unit of the marine outboard engine to the transom of a boat. The drive unit includes the internal combustion engine and propeller. The marine outboard engine is typically designed so that the steering angle and the tilt/trim angles of the drive unit relative to the boat can be adjusted and modified as desired. The bracket assembly typically includes a swivel bracket carrying the drive unit for pivotal movement about a steering axis and a stern bracket supporting the swivel bracket and the drive unit for pivotal movement about a tilt axis extending generally horizontally. The stern bracket is connected to the transom of the boat.
Some marine outboard engines are provided with a hydraulic linear actuator connected between the stern and swivel brackets for pivoting the swivel bracket to lift the lower portion of the outboard engine above the water level or, conversely, lower the lower portion of the outboard engine below the water level. Some marine outboard engines are also provided with a distinct hydraulic linear actuator for pivoting the swivel bracket through a smaller range of angles and at slower rate of motion to trim the outboard engine while the lower portion thereof is being submerged. Some marine outboard engines are also provided with a hydraulic linear actuator connected between the swivel bracket and the drive unit for pivoting the drive unit about the steering axis in order to steer the boat.
In order to operate the one or more hydraulic actuators, hydraulic fluid needs to be supplied to the actuators, which requires one or more pumps, hydraulic fluid reservoirs, and multiple valves and hoses. Due to the fairly complex and bulky mechanical structure of the bracket assembly provided with the hydraulic actuators, the pumps and reservoirs are typically provided inside the boat. This can take up valuable space inside the boat and requires the routing of hoses between the pumps and actuators which can be cumbersome. Furthermore, the installation of the pumps and the connection of the pumps and hoses with the reservoirs, valves, and actuators can be time consuming and can lead to hoses being improperly connected or connected to the wrong component. For example, the hoses to be connected to each end of the hydraulic actuator used for steering, if connected backwards, lead to the boat being steered in the direction opposite to the intended direction.